/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     | Version:     4.1
    \\  /    A nd           | Web:         http://www.foam-extend.org
     \\/     M anipulation  | For copyright notice see file Copyright
-------------------------------------------------------------------------------
License
	This file is part of foam-extend.

	foam-extend is free software: you can redistribute it and/or modify it
	under the terms of the GNU General Public License as published by the
	Free Software Foundation, either version 3 of the License, or (at your
	option) any later version.

	foam-extend is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
	General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with foam-extend.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "STLsurfaceFormat.H"
#include "ListOps.H"
#include "triPointRef.H"

// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //

template<class Face>
inline void Foam::fileFormats::STLsurfaceFormat<Face>::writeShell
(
	Ostream& os,
	const pointField& pointLst,
	const Face& f
)
{
	// calculate the normal ourselves, for flexibility and speed
	vector norm = triPointRef
	(
		pointLst[f[0]],
		pointLst[f[1]],
		pointLst[f[2]]
	).normal();
	norm /= mag(norm) + VSMALL;

	// simple triangulation about f[0].
	// better triangulation should have been done before
	const point& p0 = pointLst[f[0]];
	for (label fp1 = 1; fp1 < f.size() - 1; ++fp1)
	{
		label fp2 = f.fcIndex(fp1);

		const point& p1 = pointLst[f[fp1]];
		const point& p2 = pointLst[f[fp2]];

		// write STL triangle
		os  << " facet normal "
			<< norm.x() << ' ' << norm.y() << ' ' << norm.z() << nl
			<< "  outer loop\n"
			<< "   vertex " << p0.x() << ' ' << p0.y() << ' ' << p0.z() << nl
			<< "   vertex " << p1.x() << ' ' << p1.y() << ' ' << p1.z() << nl
			<< "   vertex " << p2.x() << ' ' << p2.y() << ' ' << p2.z() << nl
			<< "  endloop\n"
			<< " endfacet" << endl;
	}
}


template<class Face>
inline void Foam::fileFormats::STLsurfaceFormat<Face>::writeShell
(
	ostream& os,
	const pointField& pointLst,
	const Face& f,
	const label zoneI
)
{
	// calculate the normal ourselves, for flexibility and speed
	vector norm = triPointRef
	(
		pointLst[f[0]],
		pointLst[f[1]],
		pointLst[f[2]]
	).normal();
	norm /= mag(norm) + VSMALL;

	// simple triangulation about f[0].
	// better triangulation should have been done before
	const point& p0 = pointLst[f[0]];
	for (label fp1 = 1; fp1 < f.size() - 1; ++fp1)
	{
		label fp2 = f.fcIndex(fp1);

		STLtriangle stlTri
		(
			norm,
			p0,
			pointLst[f[fp1]],
			pointLst[f[fp2]],
			zoneI
		);

		stlTri.write(os);
	}
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

template<class Face>
Foam::fileFormats::STLsurfaceFormat<Face>::STLsurfaceFormat
(
	const fileName& filename
)
{
	read(filename);
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

template<class Face>
bool Foam::fileFormats::STLsurfaceFormat<Face>::read
(
	const fileName& filename
)
{
	this->clear();

	// read in the values
	STLsurfaceFormatCore reader(filename);

	// transfer points
	this->storedPoints().transfer(reader.points());

	// retrieve the original zone information
	wordList  names(reader.names().xfer());
	labelList sizes(reader.sizes().xfer());
	labelList zoneIds(reader.zoneIds().xfer());

	// generate the (sorted) faces
	List<Face> faceLst(zoneIds.size());

	if (reader.sorted())
	{
		// already sorted - generate directly
		forAll(faceLst, faceI)
		{
			const label startPt = 3*faceI;
			faceLst[faceI] = triFace(startPt, startPt+1, startPt+2);
		}
	}
	else
	{
		// unsorted - determine the sorted order:
		// avoid SortableList since we discard the main list anyhow
		labelList faceMap;
		sortedOrder(zoneIds, faceMap);

		// generate sorted faces
		forAll(faceMap, faceI)
		{
			const label startPt = 3*faceMap[faceI];
			faceLst[faceI] = triFace(startPt, startPt+1, startPt+2);
		}
	}
	zoneIds.clear();

	// transfer:
	this->storedFaces().transfer(faceLst);

	if (names.size())
	{
		this->addZones(sizes, names);
	}
	else
	{
		this->addZones(sizes);
	}

	this->stitchFaces(SMALL);
	return true;
}



template<class Face>
void Foam::fileFormats::STLsurfaceFormat<Face>::writeAscii
(
	const fileName& filename,
	const MeshedSurfaceProxy<Face>& surf
)
{
	OFstream os(filename);
	if (!os.good())
	{
		FatalErrorIn
		(
			"fileFormats::STLsurfaceFormat::writeAscii"
			"(const fileName&, const MeshedSurfaceProxy<Face>&)"
		)
			<< "Cannot open file for writing " << filename
			<< exit(FatalError);
	}

	const pointField& pointLst = surf.points();
	const List<Face>&  faceLst = surf.faces();
	const labelList& faceMap = surf.faceMap();

	const List<surfZone>& zones =
	(
		surf.surfZones().size() > 1
	  ? surf.surfZones()
	  : STLsurfaceFormat::oneZone(faceLst)
	);

	const bool useFaceMap = (surf.useFaceMap() && zones.size() > 1);

	label faceIndex = 0;
	forAll(zones, zoneI)
	{
		// Print all faces belonging to this zone
		const surfZone& zone = zones[zoneI];

		os << "solid " << zone.name() << nl;

		if (useFaceMap)
		{
			forAll(zone, localFaceI)
			{
				const label faceI = faceMap[faceIndex++];
				writeShell(os, pointLst, faceLst[faceI]);
			}
		}
		else
		{
			forAll(zone, localFaceI)
			{
				writeShell(os, pointLst, faceLst[faceIndex++]);
			}
		}
		os << "endsolid " << zone.name() << endl;
	}
}


template<class Face>
void Foam::fileFormats::STLsurfaceFormat<Face>::writeBinary
(
	const fileName& filename,
	const MeshedSurfaceProxy<Face>& surf
)
{
	std::ofstream os(filename.c_str(), std::ios::binary);
	if (!os.good())
	{
		FatalErrorIn
		(
			"fileFormats::STLsurfaceFormat::writeBinary"
			"(const fileName&, const MeshedSurfaceProxy<Face>&)"
		)
			<< "Cannot open file for writing " << filename
			<< exit(FatalError);
	}


	const pointField& pointLst = surf.points();
	const List<Face>&  faceLst = surf.faces();
	const labelList& faceMap = surf.faceMap();

	const List<surfZone>& zones =
	(
		surf.surfZones().size() > 1
	  ? surf.surfZones()
	  : STLsurfaceFormat::oneZone(faceLst)
	);

	const bool useFaceMap = (surf.useFaceMap() && zones.size() > 1);


	unsigned int nTris = 0;
	if (MeshedSurface<Face>::isTri())
	{
		nTris = faceLst.size();
	}
	else
	{
		// count triangles for on-the-fly triangulation
		forAll(faceLst, faceI)
		{
			nTris += faceLst[faceI].size() - 2;
		}
	}

	// Write the STL header
	STLsurfaceFormatCore::writeHeaderBINARY(os, nTris);

	label faceIndex = 0;
	forAll(zones, zoneI)
	{
		const surfZone& zone = zones[zoneI];

		if (useFaceMap)
		{
			forAll(zone, localFaceI)
			{
				writeShell
				(
					os,
					pointLst,
					faceLst[faceMap[faceIndex++]],
					zoneI
				);
			}
		}
		else
		{
			forAll(zone, localFaceI)
			{
				writeShell
				(
					os,
					pointLst,
					faceLst[faceIndex++],
					zoneI
				);
			}
		}
	}
}


template<class Face>
void Foam::fileFormats::STLsurfaceFormat<Face>::writeAscii
(
	const fileName& filename,
	const UnsortedMeshedSurface<Face>& surf
)
{
	OFstream os(filename);
	if (!os.good())
	{
		FatalErrorIn
		(
			"fileFormats::STLsurfaceFormat::writeAscii"
			"(const fileName&, const UnsortedMeshedSurface<Face>&)"
		)
			<< "Cannot open file for writing " << filename
			<< exit(FatalError);
	}

	// a single zone - we can skip sorting
	if (surf.zoneToc().size() == 1)
	{
		const pointField& pointLst = surf.points();
		const List<Face>& faceLst  = surf.faces();

		os << "solid " << surf.zoneToc()[0].name() << endl;
		forAll(faceLst, faceI)
		{
			writeShell(os, pointLst, faceLst[faceI]);
		}
		os << "endsolid " << surf.zoneToc()[0].name() << endl;
	}
   else
   {
	   labelList faceMap;
	   List<surfZone> zoneLst = surf.sortedZones(faceMap);

	   writeAscii
	   (
		   filename,
		   MeshedSurfaceProxy<Face>
		   (
			   surf.points(),
			   surf.faces(),
			   zoneLst,
			   faceMap
		   )
	   );
   }
}


template<class Face>
void Foam::fileFormats::STLsurfaceFormat<Face>::writeBinary
(
	const fileName& filename,
	const UnsortedMeshedSurface<Face>& surf
)
{
	std::ofstream os(filename.c_str(), std::ios::binary);
	if (!os.good())
	{
		FatalErrorIn
		(
			"fileFormats::STLsurfaceFormat::writeBinary"
			"(const fileName&, const UnsortedMeshedSurface<Face>&)"
		)
			<< "Cannot open file for writing " << filename
			<< exit(FatalError);
	}

	const pointField&  pointLst = surf.points();
	const List<Face>&  faceLst  = surf.faces();
	const labelList& zoneIds  = surf.zoneIds();

	unsigned int nTris = 0;
	if (MeshedSurface<Face>::isTri())
	{
		nTris = faceLst.size();
	}
	else
	{
		// count triangles for on-the-fly triangulation
		forAll(faceLst, faceI)
		{
			nTris += faceLst[faceI].size() - 2;
		}
	}

	// Write the STL header
	STLsurfaceFormatCore::writeHeaderBINARY(os, nTris);

	// always write unsorted
	forAll(faceLst, faceI)
	{
		writeShell
		(
			os,
			pointLst,
			faceLst[faceI],
			zoneIds[faceI]
		);
	}
}


template<class Face>
void Foam::fileFormats::STLsurfaceFormat<Face>::write
(
	const fileName& filename,
	const MeshedSurfaceProxy<Face>& surf
)
{
	const word ext = filename.ext();

	// handle 'stlb' as binary directly
	if (ext == "stlb")
	{
		writeBinary(filename, surf);
	}
	else
	{
		writeAscii(filename, surf);
	}
}


template<class Face>
void Foam::fileFormats::STLsurfaceFormat<Face>::write
(
	const fileName& filename,
	const UnsortedMeshedSurface<Face>& surf
)
{
	word ext = filename.ext();

	// handle 'stlb' as binary directly
	if (ext == "stlb")
	{
		writeBinary(filename, surf);
	}
	else
	{
		writeAscii(filename, surf);
	}
}


// ************************************************************************* //
